Divisor 9917

To determine if any number is divisible by 9917, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 47 and 211 - then it is divisible by 9917.

The following tests must pass:

• Test if a number is divisible by 47
• Test if a number is divisible by 211

Easy!